Bag



BAG

T. M. AVERY x-:rAL

Filed Jan. 11, 194s Zzglsept. 26, 1944.

Wrilllhrsillrufnusnnd/ Patented vSept. 26, 1944 UNITED 4STATES PATENTOFFICE BAG True M. Avery, Glens Falls, and William H.

Bokenkrogennudson Falls, N." Y., assignors to y Union Bag PaperCorporation, Hudson Falls, N. Y., a corporation of New JerseyApplication January 11, 1943, Serial No.472,ll24

19 Claims.

food products, such for example, as dehydrated' foods, packed in therbag or container willbe maintained in a dry state, and products, such-for example as coffee, packed in the bag'or containe;` will be kept ina moist state and the volatile or other desirable constituents thereofwill be retained, and products subject to deterioration or other adversealteration under the influence of air, moisture or other atmospheric orexterior conditions will be protected therefrom.

Another object is to provide an improved closure for bags or similarcontainers which-will be sift-proof and thus prevent the escape ofpowdery or granular material packed therein.

-Another object is to provide relatively simple and `effective meansforreinforcing the closures in opened condition, showing a section `ofthe bottom closure structure'on the line 4 4 of Fig. 3; and

Figure is a vertical section, on an enlarged scale, of*V the lowerportion of the improved bag in opened condition, the section being takenthrough the'bottom closure on the line 5,-5 in Fig. 3.

Similar parts are designated by the same reference characters in theseveral figures.

The present invention is applicable to bags of the so-called automaticand Satchel-bottom types employing the so-called "diampnd fold in theformation of the closure thereof, and to other forms of containershaving a closure of similar type. Y

` Preferably, and as shown in the present inof bags of the automatic,Satchel-bottom and similarconventional types, whereby the strengthv ofsuch closures is greatly increased.

A further object of the invention is to provide a bottom closurestructure possessing some or all of these advantages, which may beproduced effectively by heat sealing during the manufacture of the bagson bag machines of .usual or conventional form, thus enabling bagsembody.-

'lng the improved bottom blosures to be manufactured substantiallyy withthe same speed and facility, and at no substantial increase in cost ascompared with bags of the usual or conventional forms. In theaccompanying drawing, which shows the preferred embodiment of theinvention- Figure 1 shows a portion of a-,pleated and ilat` tened bagtube an end of which is opened into a so-called diamond fold,illustrating 4the man ner of inserting a sealing member during formationof the bag'y closure in accordance withthe present invention; e A Figure2 is a view similar to Fig. 1, but showing the sealing member insertedinto the closure str ucture; l

Figure 3 is a view of the completed bag bottom; Figure 4 is aperspective view, on an enlarged scale, ot the lower portion of theimproved bag walls of the tube.

y gap 9 between-them,

stance, the invention is applied to the bottom vclosure of bags of theautomatic type. Such bags may be manufactured in the usual manner andupon bag machines of the usual or well known forms from, a tube l havingpleats or tucks 2 in its longitudinal edges. The tube preferablycomprises an outer wall 3 formed from a web of ordinary paper suchasthat usually used in the manufacture of paper bags, and a coextensiveinner wall or liner 4 formed from a web of materiakwhich is'imperviousto moisture and air'ror other gases, or substantially so, and which ispreferably thermoplastic or heat scalable, such', for example, as waxpaper which is l,wax-coated and thermoplastic. on its surface the innersu'rface of the tube or bag.

,An end-of the tube formed of` such outer and inner walls, while inflattened form, is opened into a diamond f old, as shown in Fig. 1, inthe manner usual in the manufacture of bags of the automatic type uponbag machines of the usual or well known form, thus folding inwardly thepleated sides of this portion oi.l the tube to form sideflaps 5 and 6,and closing flaps l and 8 which are continuations of the lfront and backIn forming the bottoms vof bags of this type as just described, theinner'or free edges of the ilaps 5 and 6 are usually separated and forma and 'although in the completion of a bottom closure ofthis type. 'l isfolded down upon and pasted to the, underlying flaps 5 and 6, and the ap'8 is folded down upon and pasted to-underlying portions of the and flap1, crevices have been left between the flaps which were -in.communication with the gap 9 and through whichl moisture or volatile orother constituents ofthe bag contarte which forms inserted beneath theinner and '6 in a suitablemanner,

. ed on its other inner 4 posed on. the

v are preferably 5 and 6 'as l' 'thelnner portions of these tinuouslines careas of the liner could escape, or through from the atmospherecould enter the bag and thus cause deterioration of the contentsthereof. Also, such crevices and een have heretofore permitted powderyor granular material to sift out of the bag. Other gaps or leakagepoints have heretofore existed at the ends of the slits which form thetabs 'le and te, and in the regions where the adhesive squeezed away inthe direct bight of the hinge formed along the told lines il and eb whenthe naps l and ti are folded down upon the naps E and These faults inlloess oi this type as heretofore made are overcome by the presentinvention. According to this invention a sealing strip le, composed oiair and moisture 'proof material, is portions of the ii'aps Sand 5,preferably after the diamond fold has been made and before the naps Vland are folded to complete the bottom, the sealing strip bridging thegap 9 between 'the inner edges of the naps 5' and -6 throughout itslength/and preferably also extending into or overlapping partially, atleast,

secured to the preferably, however, by heat sealing. When a'liner isemployed which is provided on its inner side with a thermoplastic"coating which will bond, by heat sealing, to an uncoated surface onthe'sealing strip., it is preferable to employ a thermoplastic coatingon the of which faces the flaps 5 and but is not so coatsurface whichwill be exbag, a flexible strip wax o n one side being when thethermoinside of the of unratedv paper coated with suitable for thepurpose, and plastic coated inner surface oi the' liner will not bond,by heat sealing, to an uncoated surface of the sealing strinboth Sidesof the sealing strip thermoplastic coated. A inserted beneath thel flaps2,I and is secured to flaps along the con- II and I2, and the innerfaces of the portions of the liner within the aps 1 and '8 are -securedtothe outer and inner surfaces of the respectivend portions of thesealing strip and to one another along the continuous lines and I4, theend portion of the liner which forms part of the bottom closure of thebag being thus'sealed completely around al1 of its edges. Ll'hese linesof` sealingare preferably made by applying heat and the lines ii and l2,while tihe lligg d form as shown n atne inner surface of the sealingstrip supported out of contact with the underlying which form portionsof the inas'by a plate placed beneath the sealing strip, therebyheat-sealing the outer thermoplastic coated surface of the sealing stripthroughout the lines Il and i! to the inner ther- The sealing strip isshown in Fig.

bottom is in its Side 0f mi the support for the sealing strip, pressurealong the lines I3 and i4, thereby heat-sealing' .to one another theopposed contacting inner thermoplastic coated outer surface therepressure to the flaps ilrst along l 2, and prefersurfaoesJofthoseyportions of lines Hand ,tothef :assenso which moisture or air Vportions of the sealing strip which extend into the flaps 1 and 8.

By supporting inner surface is underlying portions of seals are madealong the lines Il4 and i2,`espe cially when the sealing strip isVthermoplastic coated on both surfaces, the heat and pressure appliedalong the line's li and l2 to heat-seal the flaps 5 and 6 to the sealingstrip will not heat-seal the inner surface of the sealing strip to thoseparts of the inner surfaces of the liner which form portions of theinside of the bag, thus avoiding interference with opening of the bagbottorninto its proper rectangular form when the baz is ed.

the sealing strip lil so that its held out of contactv with'the Thebottom closure is completed by folding and,

adhesively securing the flap 1 to the previouslyl infolded iiaps i and land folding and adhesively securing the ilap 8 tothe iiap 1 and theunderlying portions of the flaps 5 and 6 not covered by the flap 1.Ordinary paste or adhesive is preferably used for thus securing the naps1 and l, it being preferable to secure the extension tabs 1n and 8a oftheseilaps to the corresponding portions of theinner liner which overlapthem by applying paste or adhesive, for example, to those portions ofthe web which forms these portions of the outer ply or the inner liner,so that the outer and inner plies or the tabs 1"l and I will be securedtogether, and the paste or adhesive for securing the naps 1 and inclosed position may be applied in to the flaps 5 and t while these flapsare in the pleats, closure formed by a diamond form shown in Fig. 2.

Although the invention is'shown applied in ,the present instance to a vbag of the automatic type having pleats or tucks in its edges, it willbe obvious that the invention is also applicable to bags of theSatchel-bottom" type without and to any other type of bag having s', ifold, and also to other forms of containers having closures.A

Also, while the invention is applicable with particular advantages tobags having an inner nner coated on its inner surface with athermoplastic material, it is to be understood thaty the invention mayalso be applied tosingle wall bags the inner surface of which is coatedwith an air-and moisture p'roof and thermoplastic material. or to whichthermoplastic material is applied on those areas of the flaps in whichthe heat-seals are to be made as hereinbefore described.

The improved closure provided by the present invention will not onlyseal the contents from the escape of moisture or volatile substances andentrance of moisture or air which would cause deterioration or loss ofdesirable qualities thereof. but it also provides a sift-proof closurewhich'will effectively prevent the loss of powdery or lar substancespacked inthe bags. The air ani napsand nrmly connecting their inneredges and similar forms of the bag while the heatI the usual manner tothese flaps and .v

extending into and folded with said'omsmg naps,

vthe inner and outer plies of each closingfiap back walls and over saidside naps, and a sealing A member heat sealed tothe inner surfaces ofsaid side flaps and rmly connecting them, and extending into saidclosing flaps between the plies thereof and heat-sealed therein, theinner and outer plies of each closing flap being heat-sealed to oneanother and to interposed portions of said sealing member. Y g

3. A bag closure comprising flaps folded inwardly from its sides andclosing aps folded from its front and back walls, said side and closingflaps having heat-scalable inner surfaces, and a sealing stripc having aheat sealable outer surface heat-sealed to the inner surfaces of theside iiaps and bridging a gap between the latter, end portions ofthesealing strip overlapping the closing flaps, and the inner surfaces ofthe closing flaps being heat sealed to said end portions of the sealingstrip.

4. A bag closure comprising aps .folded inwardly from its sides'andclosing flaps folded fromgits front and back walls, each of the closingiiaps embodying innerandouter plies, the

inner surfaces of the side flaps and the opposed surfaces of the innerplies of the closing naps being Aheat-scalable, and a sealing striphaving.

a thermoplasticlmaterial on its outer surface lheat-sealedv to the innersurfaces of the side iiaps and having portions extending Ninto theclosing flaps, the inner surface of the sealing strip exposed fto theinterior of. the bag being devoid of thermoplastic material but theinner and outer surfaces-of the portions of the sealing strip extendinginto the closing aps being heat sealed to the'innr plies ofthe closingaps,

and the inner plies of each closing flap being heat-sealed to oneanother along a line adjacent to the fold line of the respective closingflap.

5. A closure for a bag the inner-surface of L which is air and moistureproof and heat-sealable, comprising flaps folded inwardly from the sidesof the bag and closing flaps folded from the front and back wallsthereof and onto the siderilaps, the closing iiaps having inner andsurfaces of the side flaps across outer plies, and a sealing stripcomposed of air. .and moisture proof material both surfaces -of whichare heat-scalable' and the outer surface of which is heat-sealed to theinner surfaces of the side'fiaps continuously across the width thereof,and the inner plies of each closing flap being heat sealed to the innerand outer sury faces of said" sealing strip and to one anothercontinuously across the width vthereof on a line adjacent to flap'. l i

6. A closure for a bag having an outer wall ,and an inner air andmgoisture proof liner the inner surface yof .which is providedwith athermoplastic coating, comprising `flaps -folded' from the sides of thebag land closing flaps-'folded from the front and back walls'thereof andonto the sideiiaps andY embodying innenand outer plies of said outer'wall and inner liner, and a strip of air andA moisture proof material,said strip being provided on at least its outer surface with athermoplastic coating which is heat-sealed" to the inner surfaces of theside naps, and the ends of said strip extending into closing naps '.60the fold line of the respective closing.

neV

^ closing flaps folded on ing inner and outer plies of the liner, and anair between the plies of the liner, and the plies off the liner in theclosing flaps being heat-sealed to one another and to both sides of saidstrip along lines parallel and adjacent to the fold lines of the closingflaps.

7.7A closure for a. bag having an outer wall and an inner airandmoisture proof liner, comprising flaps folded inwardly from thesides'ol",

the bag and closing flaps folded from the front and back walls thereof'onto the side folds and embodying inner and outer plies of the liner,the

and the plies of the portions of the liner forming parts of the closingnaps beingf heat 'sealed' to ode another and to the respective sides ofsaid s p.

8. A bag comprising an outer wall and an' inner air and moisture proofliner having a thermoplastic inner surface, said wall and liner having adiamond fold forming side fiaps and multiple closing flaps folded.

across the side folds and heat-sealed to the inner the Width thereof,portions of said strip extending into the closing flapsbetween plies ofthe liner and having its inner and outer surfaces respectivelyheatsealed thereto, and plies of the liner in the closing flaps beingheat-sealed to one another' across the width of the closing flaps.

9. A bag comprising an outer wall of paper and an inner air and moistureproof liner`having a thermoplastic inner surface, said outer wall andliner being diamond folded to form side flaps, and

the side flapsand embodyand moisture proof strip having a coating ofthermoplastic material on its outer side which'is heat-sealedA to theinner surfaces of the portions of the nner forming tions of said stripextending into the closing-naps between the plies of the liner therein.and said plies of the liner` in tho closing naps being neatsealed to oneanother and to both surfaces of said `strip along lines parallel andadjacent to the fold lines of the closing'naps.A

10. A bag of the automatic type comprising an outer wall' of paper andan .inner air and moisture proof liner having a thermoplastic innersurface, said outer wan and liner being -folded to form side napsextending toward one another, and closingrfiaps folded onto thesideflaps and one upon another, and each embodying'ainner and p outer pliesof the liner, and an' air and moisture across the adjacent portionsproofstrip extending of the side'naps and having'a coating of thermo.-

i plastic material on its outer surface which is heatsealed to the innersurfaces of the side naps, the ends of the strip extending into theclosing iiapsl between` the plies of the liner therein, andi the pliesof the liner in the closing aps being" heatsealed to one anotherani ofthe ends of the strip.

`11, A bag comprising an outer, wall of poner i and aninner air andthereon, and a stripV of au- Vand moisture proof material extendingparisof the side flaps, por- 4 to the respective sides.

`to the inner surfaces f thereof heat-sealing i of the side of'sald ofan outer 'and moisture proof liner having a a thermoplastic innersurface, said outer wall and liner being folded to'form side flaps, andclosing flaps folded on the slde flaps and embodying inner and outerplies of the liner, and an air and moisture proof strip extending acrossthe width of the -v side flaps and having a coating of thermoplasticmaterial on its outer surface which is `heat sealed of the portions ofthe liner forming parts of the liner in the closing flaps being heatsealed toone another, and the portions of the liner forming parts ofthe; side and closing flaps being secured 'adhesively to paper formingparts of said flaps, and the closing flaps being secured adhesively toone another and to the side flaps.

12. The method of forming a. bag closure, comprising diamond folding anend of a bag -tube having atherinoplastic inner surface tc form a pairof side aps and [closing flaps, inserting a strip IYhaving athermoplastic surface thereon beneath the side flaps in a position tobridge a gap between them, heat-sealing the inner surfaces of the sideflaps to the outer thermoplastic surface of said strip while leaving theinner surface of said stri-p j aledto the surfaces of the bag which areexposed to the interior thereof, and folding and securing the closingflaps to one another and to the side aps.

13. The method of forming a bag closure, comprising diamond folding anend of a bag tube having a thermoplastic inner surface to form a pair ofside aps extending toward one another and a pairof closing flaps eachcomposed of pairs of inner and outer plies, inserting a stripthermoplastic surface thereon beneath the side flaps in a position tobridge the adjacent edges the inner surfaces of the side l flaps to theouter thermoplastic surface of said 'strip while the inner surface ofsaid strip and the surfaces of the bag exposed to the interior thereofare in non-sealing relation, heat sealing the plies in each of theclosing flaps toA one another, and folding and securing the closingflaps to one another and to the outer sides of the side flaps.

14. The method of forming a bag closure, comprising diamond folding anend of a bag tube composed of an outer wall of paper and an inner airandmoisture proof liner having a thermoplastic inner surface to form apair of side flaps extending toward one another and a pair of closingflaps, inserting a strip which is thermoplastic on one only beneath theside flaps bridge aspace between them and the plosing flaps.heatpsealing the inner surfaces of those .portionsof thel said stripwhile avoiding sealing of the inner surstrip to the surfaces of the bagwhich are exposed to the interior thereof, heat sealing plies'of thoseportions of the liner which form parts of the closing flaps Bothsurfaces of said strip, and folding and securing the closing naps to oneanother and to the side naps.

15. The method of forming a bag closure, comprising diamond folding anend of a 'bag tube coinwall of paper and an inner air thermoplasticinnersurface to form a pair o f side flaps extending toward one anotherand l a pair of closing naps, inserting a strip which is thermoplasticon both surfac beneath the side naps in a position to bridge a spacebetween'them andto extend into the portions of the outerwall ofhaving ain a position to to extend into toone another-and to side aps, the pliesof the inner surfaces of those portions the closing flaps, heat-sealingthe inner fsurfaces of those portions of the liner which form parts ofthe side flaps to the outer s vrface of said strip while preventingsealing of the inner surface of said strip to the surfaces of the bagwhich are exposedto the interior thereof. heat-sealing plies of thoseportions of the liner which form parts of the closing flaps to oneanother and to both surfaces of said strip, and folding and securing theclosing flaps to one another and to the side naps. i

16. The method of forming a bag closure, comprising diamond folding anend of a bag tube composedof an outer wall of paper and an inner air andmoisture proof liner having a thermoplastic inner surface to form a pairof side flaps extending toward one another and a pair of closing flaps,inserting a strip beneath the side flaps in a position to bridge a spacebetween them and to extend into the closingiiaps, heat-sealing the' ofthe liner which form parts of the side flaps to the outer surface ofsaid strip while supporting the inner surface of said strip out ofsealing relation with underlying portions of the bag, and then removingsuch 1 support for the strip, heat-sealing plies of those portions ofthe liner which formparts of the closing flaps to one another and toboth surfaces of said strip, and folding and securing the closing flapsto one another and to theside flaps.

17. A closure for a moisture proof container comprising opposed flapsfolded toward one another and closing naps folded over the opposed napsand having inner and outer plies, and a moisture proof sealing strip ofa length greater than the width of the opposed naps and of a width lessthan that of the closing' flaps, said strip being sealed to opposedflaps, and the inner and outer plies vof the closingiiaps being sealedto one another and to the respective opposite surfaces of said strip.

18. A moisture proof container'havingj at an end thereof diamond-foldedside flaps. and a pair'V of closing flaps folded over the side flaps andcomprising-inner and outer plies. and a moisture proof sealing stripconnecting the inner margins f of the side flaps and extending acrossthe inner vvposite sides. of the Y which extend across liner which formparts flaps to the thermoplastic surface of surfaces thereof and betweenthe closing flaps, the plies of the closing flaps being sealed to oneanother and to the respective'opstrip 'oncontinuous linesy the widths ofthe closing flaps, and the strip being sealed tothe inner surfaces ofthe side yiiaps on continuous lines which join the sealing lines on theclosing flaps.

19. A bag comprisinga w'ali composed of moishaving at one end op-fv tureproof material and posed flaps folded toward one another and closingflaps folded over and secured to .said opposed I lxrles.v

flaps, the closing flaps each having innerand outer plies, and amoisture proof sealingstrip V.'

connecting the .inner edges of the opposed naps and lextending acrossthe inner/surfaces and between the plies of the closing naps, the pliesof the-closing naps being heat-sealed to one another and to of thesealing strip on linea which extend transverseiy of the closing mpc. andthe winamp being heat-sealed to the inner surfaces o`f theopposed napson dlines 'raux u. Aimar. wmum'n. nomxaoosa.

the inner surfaces of the Y plies of the the respective-opposiv te\surfaces which-Join said

